I'm on a Mac. My partner is on PC. same result with Firefox, Safari and IE.

We also noted that we could not logout one the frontside. Same Error message. But that one stopped????
Also every page on the site gave that error message for about 10 min. Then it stopped. Sites back.
(BTW I have a dedicated server. And it didn't crash during this time period. My other 25+ sites behaved normally.)